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Query: UMLS:C0348321 (Haemophilus)
 15,372 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A total of 314 strains of Haemophilus, isolated from clinical samples, were studied for the production of beta-galactosidase and beta-xylosidase. None of the H. influenzae strains studied (9 beta-lactamase positive strains and 129 beta-lactamase negative strains) possessed these enzymes. Both enzymes were almost constantly observed among strains of H. paraphrophilus (10 strains studied) and of H. paraphrohaemolyticus (9 strains studied). Among the other species (H. parainfluenzae, 55 strains; H. haemolyticus, 5 strains; H. parahaemolyticus, 97 strains), beta-galactosidase was present in about 30% of the strains studied whereas beta-xylosidase was detected occasionally (3% of the strains studied). Detection of these two enzymes could be a valuable test for the taxonomic study of the genus Haemophilus. However, the type of substrate used for the detection of beta-xylosidase is important: use of the para-nitro-phenyl-beta-xylopyranoside yielded more positive results than the use of its ortho-isomer.
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PMID:Significance of the detection of beta-galactosidase and of beta-xylosidase in the taxonomic study of the genus Haemophilus. 11 91

The in vitro activity of piperacillin, a new semisynthetic piperazine penicillin derivative, was evaluated against 626 clinical isolates and compared with the activity of other beta-lactam antibiotics. At a concentration of 0.1 microgram/ml, piperacillin inhibited all streptococci except enterococci. Non-beta-lactamase-producing staphylococci were inhibited by 1.6 microgram or less per ml. Both beta-lactamase- and non-beta-lactamase-producing Haemophilus were inhibited by 0.1 microgram/ml. Piperacillin inhibited non-beta-lactamase-producing Escherichia coli, Salmonella, and Shigella at a concentration of 6.3 micrograms/ml, but 20% of strains of these species containing type III beta-lactamase were not inhibited by 100 micrograms/ml. Piperacillin at 25 micrograms/ml, inhibited 83% of Citrobacter, 58% of Klebsiella, 88% of Enterobacter, and 50% of indole-positive Proteus, Acinetobacter, and Providencia. At 25 micrograms/ml, piperacillin inhibited 95% of Pseudomonas aeruginosa and 78% of Bacteroides fragilis. The minimal inhibitory concentration of piperacillin against Pseudomonas was affected by increasing the inoculum size and by pH. Minimum bactericidal concentrations against Pseudomonas and Serratia often were eightfold greater than the minimum inhibitory concentrations. Piperacillin was equal in activity to ampicillin against enterococci. It was more active than carbenicillin against E. coli, Klebsiella, Enterobacter, and Bacteroides. It was the most active penicillin against Pseudomonas and inhibited many strains of Pseudomonas for which the MICs of carbenicillin were above 200 micrograms/ml. Piperacillin was hydrolyzed by many different beta-lactamases. Synergistic activity of piperacillin was demonstrated when it was combined with amikacin, gentamicin, and cefazolin against P. aeruginosa and members of the Enterobacteriaceae. No antagonism was observed when piperacillin was combined with aminoglycosides; however, antagonism was observed rarely against E. coli when piperacillin was combined with cefazolin.
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PMID:Piperacillin, a new penicillin active against many bacteria resistant to other penicillins. 12 19

The in vitro activity of cefuroxime, a cephalosporin antibiotic, was investigated against 604 isolates and compared with the activity of other beta-lactam compounds. Cefuroxime had activity comparable to that of other cephalosporins, including cefamandole and cefoxitin, against streptococcal and staphylococcal species; most streptococci were inhibited by 0.1 mug or less per ml, and staphylococci were inhibited by 1.6 mug or less per ml. Enterococci were relatively resistant. Cefuroxime inhibited beta-lactamase-producing Neisseria gonorrhoeae and Haemophilus influenzae. Cefuroxime had excellent activity against members of the Enterobacteriaceae; 83% of beta-lactamase-producing Escherichea coli, 100% of Salmonella, 100% of Klebsiella, 90% of Proteus mirabilis, 95% of Citrobacter, 56% of Enterobacter, and 58% of Shigella were inhibited by 12.5 mug/ml. Cefuroxime had activity comparable to that of cefamandole and cefoxitin; it inhibited isolates of E. coli and Klebsiella resistant to cefamandole and inhibited Enterobacter and Citrobacter resistant to cefoxitin. Many isolates of Serratia, some indole-positive strains of Proteus, and Bacteroides fragilis were resistant to cefuroxime. Resistance of cefuroxime to hydrolysis by beta-lactamases played a major role in its activity against both gram-positive and gram-negative organisms.
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PMID:Cefuroxime, a beta-lactamase-resistant cephalosporin with a broad spectrum of gram-positive and -negative activity. 24 68

The antibacterial activities of three aminopenicillins ampicillin, epicillin and amoxycillin were compared in vitro and in vivo. The minimum inhibitory concentrations (MIC) of the three penicillins were very similar and the compounds were active against non-beta-lactamase-producing strains of Escherichia coli, Salmonella and Shigella species, Proteus mirabilis, Haemophilus influenzae and Neisseria gonorrhoeae. Streptococci including Streptococcus faecalis, and non-beta-lactamase-producing staphylococci were also sensitive to the compounds but Pseudomonas aeruginosa, Klebsiella aerogenes, Enterobacter and indole-positive Proteus species were resistant. At concentrations close to MIC value epicillin and ampicillin showed similar bactericidal activity against E. coli and against S. typhi and both compounds caused a slower rate of kill than was seen with amoxycillin. Microscopical observation of the cells exposed to ampicillin and epicillin for 1 h showed the presence of filamentous forms which lysed slowly, whereas cells exposed to amoxycillin for the same period rapidly. Epicillin was similar to or slightly less active than ampicillin against experimental mouse infections, and against the majority of infections both compounds were significantly less effective than amoxycillin by the oral and subcutaneous routes of administration.
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PMID:Comparative activities of ampicillin, epicillin and amoxycillin in vitro and in vivo. 25 24

Inhibitory activity of cephalexin, cephradine, and cefaclor was compared by the WHO-ICS agar dilution technique. Cefaclor was substantially more active against staphylococci, streptococci, gonococci, meningococci, Haemophilus, Escherichia coli, Klebsiella pneumoniae, Citrobacter diversus, Proteus mirabilis, salmonellae, and shigellae than was cephalexin, which in turn was more active than cephradine. Cefaclor appeared to be less resistant to staphylococcal penicillinase than did the other two agents. None of these cephalosporins was active against Enterobacter, Serratia, indole-positive Proteeae, Pseudomonas, or Bacteroides fragilis.
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PMID:Comparison of in vitro activity of cephalexin, cephradine, and cefaclor. 30 Oct 5

On the basis of their susceptibility to ampicillin, strains of Haemophilus influenzae can be divided into three types: type 1 are normally susceptible strains, type 2 produce stable spheroplasts from low inocula, and type 3 are beta-lactamase producers. Because of the production of spheroplasts, standard broth and agar dilution techniques have failed to differentiate between the responses of type 2 and 3 strains to ampicillin, or to identify the superiority of cefuroxime over ampicillin against the beta-lactamase-producing strains. Disk susceptibility tests with heavily seeded plates were also difficult to interpret. To overcome these problems, we developed a medium that supports the growth of H. influenzae, but not survival of spheroplasts, thereby reducing the complicating influence of spheroplast formation. Utilization of the medium made it possible to identify beta-lactamase-producing strains via both minimal inhibitory concentration and disk susceptibility techniques, as well as the superiority of cefuroxime over ampicillin against such strains. In vivo experiments showed that cefuroxime and ampicillin are equally active against infections with type 1 and 2 strains, but that cefuroxime is superior to ampicillin against infections with type 3 beta-lactamase-producing strains.
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PMID:Comparative acitivity of ampicillin and cefuroxime against three types of Haemophilus influenzae. 30 Oct 7

The capillary beta-lactamase test for the detection of Haemophilus influenzae resistance to ampicillin was evaluated against 132 strains of H. influenzae recently isolated from clinical materials and four reference strains. Nineteen strains, including two of serotype b, were beta-lactamase-positive. The minimal inhibitory concentrations (MIC) of ampicillin for the 117 beta-lactamase-negative strains ranged from less than or equal to 0.125 to 2 microgram/ml (only one strain had a MIC of 2 microgram/ml). The range of MIC's of ampicillin was 4 to 64 microgram/ml for the 19 beta-lactamase-positive strains; all but two strains required 8 microgram/ml or more for inhibition. The capillary beta-lactamase test is an easy, rapid and reliable test for the detection of H. influenzae resistance to ampicillin. It is suitable for routine use in the clinical microbiology laboratory. The MIC of carbenicillin was higher for ampicillin-resistant than for ampicillin-susceptible strains, but the highest MIC (32 microgram/ml) was within achievable serum concentrations. Both cefamandole and chloramphenicol were active against all strains.
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PMID:Evaluation of the capillary beta-lactamase test and antimicrobial susceptibility of Haemophilus influenzae. 30 42

Intraperitoneal injections of 250 mg of ampicillin per kg every 6 h for 30 h sterilized the blood and cerebrospinal fluid of infant rats infected with either a beta-lactamase-containing strain of Haemophilus influenzae type b or a strain lacking the enzyme. However, a single injection of 100 mg/kg sterilized the blood and cerebrospinal fluid of significantly fewer of those rats infected with the beta-lactamase-producing strain. The results suggest that resistance of beta-lactamase-containing strains of H. influenzae in vivo may be inoculum dependent, as demonstrated previously in vitro. The infant rat model appears suited for the quantitative delineation of the effect of beta-lactamase on the treatment of H. influenzae bacteremia and meningitis with beta-lactamase antibiotics.
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PMID:Beta-lactamase effect on ampicillin treatment of Haemophilus influenzae B bacteremia and meningitis in infant rats. 30 97

Three methods for rapidly detecting beta-lactamase activity in Haemophilus influenzae are compared. The chromogenic cephalosporin method was found to be the most easily performed and the reagents could be stored for up to three weeks. The phenol red method was simple to perform but the iodometric method was more time consuming. All three tests gave identical results.
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PMID:A comparison of three rapid methods for the detection of beta-lactamase activity in Haemophilus influenzae. 30 72

Ampicillin-resistant Haemophilus influenzae does occur now in the FRG. In one isolate a plasmid with resistance genes (R-factor) could be demonstrated as cause of the ampicillin resistance. This R-factor influences production of a beta-lactamase of the TEM type which destroys ampicillin. The infectious nature of the ampicillin resistance was proven by the fact that it was transferable to other bacterial species through cocultivation. Parallel to ampicillin resistance tetracycline resistant Haemophilus influenzae has occurred in the FRG. Here the resistance was equally bound to plasmids. These R-factors are infectious as well. Molecular analysis of the 3 isolated resistance factors in Haemophilus influenzae showed that they carry the same resistance genes which are known from R-factors of Enterobacteriaceae. In the therapy of purulent infections due to Haemophilus influenzae such as childhood meningitis one can no longer rely on general ampicillin sensitivity of the offender. Apart from ampicillin and tetracycline resistant Haemophilus influenzae chloramphenicol resistance has been observed in a few cases.
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PMID:[Infectious resistance to antibiotics in Haemophilus influenzae (author's transl)]. 30 40


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